Theoretical Study on Water Gas Shift Mechanism on Monatomic Transition Metal M Supporting Mos2 Catalyst (M=Co, Ni, Cu)

Abstract

In this paper, a two-dimensional M/MoS2 material system was constructed by supporting transition metal atoms M (M=Co, Ni, Cu) on the surface of MoS2. The structural properties, molecular adsorption and the reaction mechanism for water gas shift reaction (WGSR) were investigated based on DFT calculation. Compared with pristine MoS2, doping transition metal can make M/MoS2 more stable because the charge transfer between metal and MoS2 increases the polarization of Mo and S. The adsorption performance is significantly improved, which is conducive to the forward progress of the reaction. The band gap of materials is narrowed, which motivates MoS2 transforms to metal phase. The supporting metal can increase the charge transfer and the number of active sites in the system, which can effectively reduce the reaction energy barrier of WGS and improve the catalytic activity. The most potential WGSR mechanism of the three materials is the association mechanism, in which the HCOO* intermediate plays the leading role.

Keywords: Water gas shift reaction (WGSR), Density functional theory (DFT), 2D material, Transition metal supporting, Reaction mechanism